The interplay of volcanism, stream erosion and landslides is evident
in this Shuttle Radar Topography Mission view of the eastern flank of
the Andes Mountains, southeast of San Carlos de Bariloche, Argentina.
Older lava flows emanating from the Andes once covered much of this
area. Younger, local volcanoes (seen here as small peaks) then covered
parts of the area with fresh, erosion resistant flows (seen here as very
smooth surfaces). Subsequent erosion has created fine patterns on the
older surfaces (bottom of the image) and bolder, irregular patterns
through and around the younger surfaces (upper center and right center).
Meanwhile, where a large stream immediately borders the resistant
plateau (center of the image), lateral erosion has undercut the
resistant plateau causing slivers of it to fall into the stream channel.
This scene well illustrates how topographic data alone can reveal some
aspects of recent geologic history.

Two visualization methods were combined to produce this image:
shading and color coding of topographic height. The shade image was
derived by computing topographic slope in the north-south direction.
Northern slopes appear bright and southern slopes appear dark, as would
be the case at noon at this latitude in the southern hemisphere. Color
coding is directly related to topographic height, with green at the
lower elevations, rising through yellow, red, and magenta, to white at
the highest elevations.